The invention concerns a device for winding and unwinding a web of material and having two separated uprights, in each of which is mounted a horizontal chuck that the core tube can be introduced into.
Devices of this type, wherein the reel is tensioned without a shaft between the chucks and secured by them while being wound or unwound, are employed in particular for winding and unwinding webs of paper in the paper-processing industry. Unwinding devices of this type are described for example in German GM 8 511 986 and German OS 2 951 336. Winding devices with these characteristics are disclosed in German OS 3 308 271.
Attempts are always being made in the paper-processing industry to handle increasingly larger and hence heavier reels in order to decrease the downtimes that occur while the reels are being changed. The known winding and unwinding devices, however, can be employed only to wind and unwind reels up to a particular weight, because the core tubes of heavier reels tend to corrugate and tear.
This drawback occurs frequently in the unwinding of heavy reels (60-70 kN) of thin papers with short-diameter core tubes and increases the rate of rejection during subsequent processing of the webs of paper, in salvage winders for example.